Steve Mann on his 35-year history building and wearing computerised eyewear. "Was it blind luck (pardon the expression) that I was wearing this vision-enhancing system at the time of the accident? Not at all: I have been designing, building, and wearing some form of this gear for more than 35 years." Glass has the potential to have a huge impact on the world - and just like with the advent of the mobile phone, people are afraid, cynical, and unable to see the possibly huge benefits of systems like this.